JPH04230470A - Energy absorption system - Google Patents

Abstract

PURPOSE: To provide a system for absorbing the energy applied from the outside by moving deforming members and deformable members relative to each other, and allowing the deforming members to deform the deformable members so as to reduce the overall length at the time of a collision accident of a vehicle. CONSTITUTION: This system is provided with nearly U-shaped deformable members 1, 6, 9, 10, 30, 81 and deforming members 3, 5, 21, 80 arranged apart from the deformable members during inactivation, and both members can be moved relative to each other. During activation, the deforming members 3, 5, 21, 80 deform the deformable members 1, 6, 9, 10, 30, 81 respectively to reduce the overall length of the deformable members in the direction of both legs of U-shapes. The members can be shaped and dimensioned to give the desired energy absorption characteristics.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates particularly, but not exclusively, to energy absorption systems for shock absorbing steering shafts for vehicles.

0002

BACKGROUND OF THE INVENTION Shock absorbing steering shaft systems are well known. One such steering shaft tube arrangement with energy absorbing elements is disclosed in US Pat. No. 4,786,076. In this device, the energy absorbing element is a shear plate forming part of a U-shaped structure attached to the steering shaft tube. A bolted connection secures both the shear plate and its U-shaped support bracket to the vehicle frame. The force required to break the shear plate is therefore extremely dependent on the preload applied to the bolted connection;
To obtain variable adjustment of this frictional force, special cup springs are attached to the bolted connections. A protective cylindrical steering element is also attached to the steering shaft. It is fastened to the steering shaft tube in such a way that the impact loads occurring on this protective element are transmitted to the steering shaft tube. The side loads coming from this area are therefore added to the direct loads acting on the steering wheel, making it difficult to obtain an equal proportion of energy absorption for the steering shaft itself.

An alternative device is disclosed in US Pat. No. 4,117,741. In this device, the energy absorbing member is in the form of a simply supported beam with a section with a reduced cross section and with bolted end connections. This bolted connection is returned to the vehicle frame, so it is difficult to discern a difference between the restraining load and the deformation load. During impact, the distorted shape of the energy absorbing member occupies a larger space than its original undistorted shape. This can be a disadvantage in steering shaft tube assemblies where space is at a premium.

0004

[Means for Solving the Problems] According to the present invention, approximately U
a deformable member spaced apart from the deformable member in an inoperative position, the deformable member being movable relative to the deformable member such that upon actuation the deformable member is capable of deforming the deformable member; An energy absorption system is obtained in which the member material is deformed to reduce the overall length of the deformable member in the direction of the legs of the U-shape and while doing so absorb energy.

In a preferred embodiment of the invention, the system forms part of a shock-absorbing steering shaft arrangement for a vehicle of transportation, such as a motor vehicle or a motorboard. The deformable member is connected to the fixed support of the steering axle, and the deformable member to the steering axle itself, and vice versa. The deformable member may be of any suitable material, but mild steel is preferred. The shape and dimensions of the deformable and/or deformable member are selected to provide the desired energy absorption properties. The deformable member may be parallelepiped or cylindrical. The deformable member may also be contoured with energy absorbing protrusions that adapt to changes in impact to produce uniform energy absorption.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: FIG.

[0007] First, the drawings shown in FIG. 1(a) and FIG.
Regarding b), the basic principle behind the present invention will first be explained. FIG. 1a shows a perspective view of an elongated U-shaped energy-absorbing deformable member 1 and a parallelepiped deformable member 3 spaced therefrom. In a vehicle steering axle arrangement, element 1 is connected to the vehicle support and element 3 to the steering axle, and vice versa, as will be explained in more detail below. In FIG. 1(a), member 1
The normal inoperative position of the undeformed system is shown. FIG. 1(b) shows FIG.
The system in (a) is shown. Upon said impact, the deformable member 3 applies an impact to the deformable member 1 such that the deformation of the base of the initial U-shape produces a secondary U-shape, thereby reducing the effective length of the member 1. to deform the member 1. It is in this variant that the energy of the driver moving forward with a considerable speed difference compared to the vehicle, as occurs in the event of an accident, is absorbed in a controlled manner. This in turn reduces the risk of injury to the driver. The required load for initial deformation is the width (W
) can be changed by changing (see (a) in Figure 1)
. The larger the dimension (W), the greater the load initially required to deform the member 1.

FIG. 1(c) shows the configuration of FIGS. 1(a) and 1(b) in which the deformable member 5 is cylindrical and acts on a U-shaped deformable member 6. A modification of the device is shown. The selection of the diameter of the cylindrical deformable member 5 is
7 and 8 to a significant extent,
This in turn influences the initial load required to deform the member 6. Small curvatures require more energy to deform than large curvatures.

[0009] The load absorption degree can be predetermined in other ways. In addition to changing the material of the deformable member, the deformable member can be shaped to affect load absorption. For example, FIG. 2(a) shows a deformable member 9 having a change in cross-section so that the degree of load absorption changes when the deformable member is bent back onto itself. There is. FIG. 2b shows a deformable member 10 having a more complex profile with protrusions at 11 and 12 to obtain fundamentally uniform load absorption, as explained below. There is. The holes 13 are for facilitating the pin connection of the deformable member to its support member. The main advantage of the deformable member in the system according to the invention is that even if the deformable member starts at a length (L) as shown in FIG. As it rewinds to (
As shown in b), the dimension (L) becomes shorter. This is important in steering shaft tube assemblies where space is at a premium. Furthermore, the material of the deformable member is first formed into a curved shape and then stretched straight again and rolled back onto itself twice, thus increasing the degree of processing and producing more for the same amount of material. It will be appreciated that this results in an energy absorption of . It will also be appreciated that the deformable member acts to guide the material as the deformable member is moved and also causes deformation.

3-6 illustrate an energy absorption system of the type described above implemented within a vehicle steering shaft tube assembly.

[0011] The vehicle steering system includes a top portion (not shown).
and a steering shaft tube assembly 14 including a steering handle 15 connected at the bottom by a conventional bearing 18 to a steering shaft 16 mounted within a steering tubular housing shaft tube 17. The steering shaft 16 is a shaft coupling 19
is connected to. A deformable element in the form of a guide fin 21 is fixedly attached to the steering housing 17, such as by welding. As shown in FIG. 5(b), the fin 21
can be contoured to effect a change in load characteristics.

T shown in detail in FIGS. 4 and 5(a)
A shaped support plate 22 is also attached to the steering tube housing 17, such as by welding. The support plate 22 is slotted at 23, 24 at the top of the T and includes a longitudinal slot 25 along the tail of the T for purposes explained below.

The steering shaft tube assembly 14 as a whole has two
It operates in conjunction with the support assembly shown in 6. Support assembly 26 includes an L-shaped main bracket 27 , a brace member 28 , and a generally inverted U-shaped main member 29 connecting between bracket 27 and brace member 28 . As shown in detail in FIG. 6, U-shaped member 29 forms a housing for deformable member 30, which is shown pinned to housing member 29 at 31.

The deformable member 30 is shown in FIG.
(b) and (c) of FIG. 1, and (a) of FIG. 2 and (b) of FIG. 2. Support assembly 26 is attached to the vehicle frame in any suitable manner.

Steering shaft tube assembly 14 and support assembly 26 are mounted for movement relative to each other in the manner shown in detail in FIGS. 4 and 6. As seen in FIG. 6, the main U-shaped member 29 has internally threaded mounting elements 32 mounted thereto at both ends 29a. The threaded fastening element 33 acts in conjunction with the mounting element 32 to
It supports a bracket member 38 (see also FIG. 3), which attaches the U-shaped member 38 to the main member 29 and to the frame of the vehicle.

An isolation disc 34 with a rubber vibration isolator insert 35 is located on the mounting element 32 and serves to isolate the steering axle assembly 14 from vibrations coming from the vehicle via the support assembly 26. There is. isolation disk 3
4 is slotted at 36 to cooperate with slots 23, 24 and also longitudinal slot 25 on plate 22. This fastening system allows steering shaft tube assembly 14 and support assembly 26 to be fastened together with a predetermined preload that is independent of impact loads that cause deformation of deformable energy absorbing member 30. Deformable energy absorbing member 30 is shown in FIG. 5(a) in an undeformed state and in FIG. 4 in a deformed state. The shear pin 37 allows the isolation disc 34 to be attached to the plate 2.
2. Therefore, before a relative movement can occur between the deformable member 21 and the deformable member 30, the fastening element 33
preload must be overcome and pin 37 sheared. Prior to said relative movement, the deformable member 21 is positioned so as not to interfere with the function of the separator attachment.

In operation, the shock load from the accident overcomes the preload of the fastening elements 32, 33, shearing the pin 37 and thus freeing the deformable member 21 towards the deformable member 30, which Figure 1 (a), Figure 1 (b)
), as discussed in FIG. 1(c), FIG. 2(a), and FIG. 2(b). In practice, energy is absorbed for the direct loads coming from the impact in the thoracic region (C) (see Figure 3) and for the additional indirect loads generated from the impact by the fascia and instrument control in the region (D). Ru. According to the present invention, for example, the deformable member 30 is designed to include the protrusions 11 and 12 shown in FIG. Uniform energy absorption can be obtained regardless of the load. Another factor that makes it difficult to achieve even load absorption is the load coming from the knee area (E), which typically impacts the steering shaft tube assembly itself. According to the invention, the impact from the knee area is received on the U-shaped member 38 (see FIGS. 3 and 6), and as described above, the impact from the knee area is received on the U-shaped member 38 (see FIGS.
is connected to the vehicle frame. Therefore, with this device, the steering shaft tube assembly is not subjected to loads from knee impacts. Figure 1 (a), Figure 1 (b) and Figure 1 (
As mentioned under c), the U-shaped member 38 cannot normally be an energy absorbing member. Although it does not do so in this embodiment, by appropriate design it may also absorb energy from the lower torso.

The preferred material for the U-shaped deformable member is mild steel.

FIGS. 7, 8 and 9 schematically show an alternative to the embodiment shown in FIGS. 3 to 6. In this alternative, the U-shaped deformable member 81 is attached to the axial tube and the deformable member 80 is attached to the axial tube support.
That is, the deformable member 21 is transferred to the shaft tube, and the deformable member 3
This is contrary to the apparatus of FIGS. 3-6, in which the 0 is attached to the axial tube support. This alternative is similar in all other respects to the embodiment of FIGS. 3-6.

It will be understood that the above embodiments have been described by way of example only and that many modifications may be made without departing from the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 (a) is a schematic perspective view of an energy absorption system before deformation. (b) is a diagram of a system similar to FIG. 1(a), but after modification; (c) is similar to (b) in Figure 1, but with an alternative system.
figure.

2(a) is a perspective view of an alternative deformable member to that shown in FIGS. 1(a), 1(b) and 1(c); FIG. (b) is a perspective view of a deformable member having another shape.

FIG. 3: (a) in FIG. 1, (b) in FIG. 1, (c) in FIG.
Figure 2 is a schematic partial cross-sectional view of a vehicle steering shaft assembly incorporating an energy absorption system of the type shown in Figures 2(a) and 2(b);

FIG. 4 is an illustrative exploded perspective view.

5(a) is a side view of a portion of the apparatus of FIG. 4, seen in the direction of arrow (B); FIG. (b) is a diagram of a fin member whose contour has been generated;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 3;

FIG. 7 is a side view of an alternative steering shaft arrangement to that of FIG. 3;

8 is a plan cross-sectional view of the device of FIG. 7 along line a-a of FIG. 7;

9 is a cross-sectional end view of the device of FIG. 7 taken along line b--b of FIG. 7;

[Explanation of symbols]

1 Deformable member 3　Deformable member 5　Deformable member 6 Deformable members 9 Deformable members 10 Deformable member 21　Deformable member 30 Deformable member 80 Deformable member 81 Deformable member

Claims (10)

[Claims] 1. In an energy absorption system, a generally U-shaped deformable member (1), (6), (9), (10) is provided.
) or (30), and the deformable member (
deformable member (3), (5) or (21) spaced apart from (1), (6), (9), (10) or (30);
and said members are movable relative to each other, whereby upon actuation said deformable member (3), (5) or (21
) is the deformable member (1), (6), (9), (10
) or (30) to form the deformable members (1), (6), (9), (
10) or (30) and is adapted to absorb energy while doing so. 2. The energy absorption system according to claim 1, wherein the deformable members (1), (6), (9)
, (10) or (30) are made of mild steel. 3. The energy absorption system according to claim 1, wherein the deformable members (1), (6), (9)
, (10) or (30) are selected to provide desired energy absorption properties. 4. The energy absorption system according to claim 1, wherein the deformable member (3), (5) or (21
), the shape and dimensions of which are selected to provide desired energy absorption properties. 5. Energy absorption system according to claim 1, wherein the deformable member (3) is in the shape of a parallelepiped. 6. Energy absorption system according to claim 1, wherein the deformable member (5) is cylindrical in shape. 7. An energy absorption system according to claim 1, wherein the deformable member (10) can be contoured with energy absorption protrusions that adapt to changes in impact and produce an even degree of energy absorption. energy absorption system. 8. A device having an energy absorption system in a collision absorbing steering shaft tube device for a vehicle, wherein approximately U
Character-shaped deformable members (1), (6), (9), (10), (
30) or (81) and a deformable member (3) spaced apart from said deformable member (1), (6), (9), (10), (30) or (81) in the inoperative position. ), (5)
, (21) or (80), and both said members are movable relative to each other, whereby said deformable member (
3), (5), (21) or (80) deforms the deformable member (1), (6), (9), (10), (30) or (81) to form the U-shape. said deformable members (1), (6), (9), (10) in the direction of both legs;
, (30) or (81) and is adapted to absorb energy while doing so. 9. A shock-absorbing steering shaft tube device according to claim 8, wherein the deformable member (30) is attached to a fixed support of the steering shaft tube and the deformable member (21) is attached to the steering shaft tube. Shock-absorbing steering shaft tube device connected to each other. 10. A shock-absorbing steering shaft tube device according to claim 8, wherein the deformable member (81) is attached to the steering shaft tube and the deformable member (80) is attached to a fixed support of the steering shaft tube. Shock-absorbing steering shaft tube device connected to each other.